This invention relates to a process for preparing perfluoroadamantane and 1-hydropentadecafluoroadamantane. More particularly, this invention relates to a process for converting adamantane or bromoadamantane to a mixture of perfluoroadamantane and 1-hydropentadecafluoroadamantane. The mixture can have utility as a synthetic blood substitute and/or a perfusion medium.
N. J. Maraschin et al. in J.A.C.S 97:3, 513-517 (Feb. 5, 1975) and G. Robertson et al. in J. Organic Chemistry, Vol 43, No. 26, 4981-4983 (1978) reports the preparation of 1-hydropentadecafluoroadamantane from adamantane using elemental fluorine (-78.degree. C. to room temperature) and requiring many hours. However, use of fluorine and a low temperature is not a viable commercial method for preparing large quantities in a short period.
Other processes involving perfluorination of cyclic hydrocarbons using CoF.sub.3 are disclosed in the U.S. Pat. Nos. 4,143,079 and 4,105,798. These patents also disclosed the use of perfluorinated cyclic carbon compounds as synthetic blood substitutes or perfusion media. U.S. Pat. Nos. 4,110,474 and 4,187,252 disclose that perfluorinated methylpentanes are useful as synthetic blood substitutes and/or perfusion media. U.S. Pat. No. 3,911,138 discloses that certain perfluorinated cyclic carbon compounds, when emulsified, can be used as blood substitutes. The five aforementioned U.S. patents are incorporated herein by reference.
However, none of the foregoing art suggests that it would be possible to perfluorinate adamantane or bromoadamantane over CoF.sub.3 without experiencing ring openings. Or that the resulting mixture of perfluoroadamantane and 1-hydropentadecafluoroadamantane would transpire from mice at a rate substantially greater than when using e.g., perfluorodecalin, a fluorocarbon considered by those skilled in the art as being a very good blood substitute.